The Constitution ( 122) Amendment Bill enabling the introduction of the goods and services tax ( GST) has recently been enacted. It is a landmark reform considering the sweeping changes it brings about in the indirect tax regime in India as well as in distribution of powers between the Centre and states vis- Ã - vis such taxes. Unfortunately, upon minute review of the amendments read with the provisions of the draft Model GST law, several constitutional issues emerge. Definition of goods The first challenge emerges in the form of the definition of ‘ goods’ and ‘services’ under the Model GST law. Since inception, ‘ goods’ was defined in the Constitution in a broad manner. Judicial decisions have thus far held goods to include intangible property such as off- the- shelf software, trademarks, and the sales tax levied on them. The definition of ‘ services’ has now been added in the Constitution as “anything other than goods”. While the Model GST law uses a similar definition for ‘ ser